Field of the Invention
The present invention relates to a high-voltage diode having an anodal p-conducting zone, a cathodal n−-conducting drift zone, which forms a pn junction with the p-conducting zone, a p+-conducting anode emitter, which adjoins an anode metalization layer and is provided in the p-conducting zone, and an n+-conducting cathode emitter adjoining a cathode metalization layer.
In the case of fast high-voltage diodes of the type mentioned above, that is to say in the case of diodes with a pn−n structure, the efficiency of the-anode emitter should be as low as possible in order to achieve an adjustable small flooding of the n−-conducting drift zone with charge carriers at the anodal end thereof and thus a small peak reverse current during commutation of the high-voltage diode.
The setting of the efficiency of the anode emitter to relatively low values is currently achieved by employing irradiation techniques or by generally reducing the p-type dose introduced into the p-conducting zone. When employing irradiation techniques, however, the crystal damage inevitably induced thereby results in a rise in the reverse current level of the high-voltage diode, while limits are imposed on a reduction through minimization of the p-type dose insofar as an excessively low p-type dose does not ensure adequate contact connection and reduces the commutation strength as well as the static blocking capability of the high-voltage diode.